Rail joint



Nov. 29, 1966 L. GROFF 3,

RAIL JOINT Filed June 18, 1965 5 Sheets-Sheet 1 FIG. 1.

INVENTOR EMORY L. GEOFF ATTORNEY E. L. GROFF RAIL JOINT Nov. 29, 1966 5Sheets-Sheet 2 Filed June 18, 1965 FIG. 8.

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H r l d Y A INVENTOR EMORY L. GROFF BY a H l f ATTORNEY E. L. GROFF RAILJOINT Nov. 29, 1966 5 Sheets-Sheet :5

Filed June 18, 1965 INVENTOR EMORY GROFF M 4 A 'ORNEY United States?atent 3,288,369 RAIL JOINT Emory L. Grotf, Pompano Beach, Fla,assignor, hy mesne.

assignments, to Poor & Company, Chicago, 11L, a corporatnon of DelawareFiled June 18, 1965, Ser. No. 464,952; 6 Qlaims. (Cl. 238243) Thisinvention relates to rail joints for connecting the ends of railsections to form a railroad track. More particularly, the inventionrelates to so-called oint bars of non-metallic material having generallyuniversal use. Heretofore, it has been customary to manufacture thesebars of high grade steel at a rolling mill in steel plants located atstrategic shipment points because of'the distance of the point of usefrom the mill. That 1s to say, under current practice, joint bars areburdened not only with the great expense of making and maintainmg manysets of rolls but also great tonnage transporta tron costs.

On the question of weight, for example, a single socalled 131# metal barto fit a 13l# rail is twenty-four inches in length, with four boltholes, and would weigh approximately 83#; and, a single thirty-six inchbar, with six bolt holes, would weight approximately 124#. With two barsto the joint, the dead weight becomes enormous.

Moreover, in the event the bars are used in sections of signal track,the block signal divisions require intervals of insulated joints. Thus,two separate and distinct classes of joint bars must now be manufacturedand made available, whereas, with the present invention, the bars inthemselves are non-conductive and may be used with a standard insulatedend post to provide an insulated joint while the rails between insulatedjoints using the bars of the present invention may be made conductivewith a metallic end post such as shown in FIG. 2 of Patent No. 3,111,264issued November 19, 1963.

Rail joint bars are in efiect a beam, intended to grip the rail endswith sufiicient force to simulate a continuous rail. It has now beenestablished that continuous rail has many objections, even when madein-situ, and jointed track has advantages quite clear to railwaymaintenance of way engineers.

Accordingly, a primary object of the invention is to provide anon-metallic relatively light-weight joint bar capable of being producedby molding techniques suitable for use in track. Preferably, the barsare made of a moldable plastic material such as glass fibers envelopedor coated with a thermosetting resin. In that connection,

since the greatest concentration of pressure is longitudinally along thecenter of the web at the bolt holes, this area is the focal point fromwhich pressure is transmitted to the head and foot to insure proper fitand rail end support. To that end, it is proposed to make rail jointbars wholly of thermosetting resins'utilizing glass rovings or strandswound about a matrix or core which remains as a part of the finishedbar. Thus, the present invention contemplates a joint pre-molded to fitthe fishing of any given steel rail section having compressive strengthcommensurate with a steel bar. The advantages attendant to such anadvancement in the art are numerous, the most important of which are theoverall economical aspects. In the case of steel bars, it is necessary,as previously indicated, to provide and maintain rolls, shears, ovens,dies and tools as well as other heavy equipment, all operated byhigh-wage personnel, while only a fraction of this effort is requiredfor manufacturing the present plastic bar. Moreover, the cost of storingand shipping is far less for the plastic bar which weighs approximatelyone-fifth of the amount of the steel bar.

Patented Nov. 29, 1966 An important use for a rail joint of plasticwould be in connection with the recently introduced electronicallycontrolled rail systems wherein a single operator sitting at a controlpanel automatically controls several unmanned trains operating over asingle rail net, for example between two distant points as ininter-urban traffie or ani ron-ore mine complex where a punch cardcontrol system'now is in operation. In such a system, electricalimpulses are transmitted through the rails to con trol the differentlocomotive engines at several different speeds and to regulate thebraking controls. The use of steel bars without adequate insulationwould interfere with the maintenance of the critical electronic circuitsbeing transmitted through the rails, contrary to the plastic bar whichis a non-conductive, non-magnetic, and non-corrosive element.

Accordingly, the principal objects are to provide a reinforced plasticjoint bar having a filler material arranged to provide maximumcompressive strength in specified areas; provide a method formanufacturing joint bars of plastic material; and also to provide amethod for the manufacture of plastic bars having a filler ofreinforcing material.

With these and other objects in view which will more readily appear asthe nature of the invention is better understood, the invention consistsin the novel construction, combination, and arrangement of partshereinafter more fully described, illustrated, and claimed.

A preferred and practical embodiment of the invention is shown in theaccompanying drawings, in which:

FIG. 1 is an end elevation of one form of a typical plastic rail jointba-r according to the present invention as it is applied to the fishingof the rail.

FIG. 2 is a side elevation of the bar shown in FIG. 1.

FIG. 3 is a vertical cross-sectional view taken on the line 33 of FIG.2.

FIG. 4 is a fragmentary side elevation of the matrix about which thereinforcing strands are wound.

FIG. 5 is a vertical cross-sectional view taken on the line 55 of FIG.4.

FIG. 6 is an elevation of another form of matrix.

FIG. 7 is a cross-sectional view taken on the line 7-7 of FIG. 6.

FIGS. 8 and 9 are fragmentary elevations of typical reinforcements to beembodied in the web of the bar.

FIG. 10 is a diagrammatic perspective view of one form of matrix encasedin a body of reinforced plastic prior to being placed in the mold.

FIG. 11 is a cross-sectional view of the mold contaming the body of FIG.10.

FIG. 12 is an end elevation of a modified form of bar fitted to a rail.

FIG. 13 is a side elevation of the bar shown in FIG. 12.

FIG. 14 is an end sectional view of a plastic bar having metal claddingapplied thereto.

FIG. 15 is a side elevation of the bar of FIG. 14.

Similar reference characters designate corresponding parts throughoutthe several figures of the drawings.

Referring to the drawings, it will be seen'that the present invention isdirected to a plastic joint bar B, such for example as a head-free baradapted to fit into the fishing space of a rail R. Currently, bars ofthis type are made in a rolling mill, and in the example illustrated thebar has the shape of a standard 131-RE rail. It will of course beunderstood that this bar is used solely for purpose of illustration, andnot by way of limitation.

The present rail joint bar is constructed generally of a syntheticplastic resin. Synthetic resins fall into two basic classifications;namely, thermoplastic and thermosetting. thermosetting resin is thedesirable type of material for the present device in preference to theuse of thermoplastic resins, since the latter are long chain compoundswhich soften upon the application of heat.

As thermoplastic compounds undergo no chemical changes and can be heatedand cooled any number of times without change, they find little use inmany structural applications, since they have limited resistance to heatand are subject to cold flow under load.

Accordingly, in the present invention, thermosetting resins are the mostdesirable compounds. The basic property of thermosetting resins is tochange under heat by polymerization to form infusable cross-linkedcompounds. Many of these compounds require heat to complete thereaction, but others, for example the epoxies, are exothermic reactionsand the heat is purely an accelerator to increase the speed of thereaction and to increase the permissible operating temperature of theresultant joint bar when put into service. Thus, the thermosetting epoxyresins are the preferred compounds for use in producing the presentinvention in view of their inherent properties. Such compounds includethe epoxy-phenolics, epoxypolyamides, epoxy-polysulphides, etc.

Even though the above resins appear to be the most suitable, numerousphenolic polyester, polycarbonate, polytrifluoroethylene, silicone, andphenol silane compounds cannot be ignored; however, the presentdescription will be confined to the discussion of a rail joint barconstructed of the epoxy type of synthetic resins.

The most desirable reinforcing can be provided by utilizing a structuralfiller in the nature of glass strands more commonly referred to as glassfibers or roving. Numerous glass fiber reinforced epoxy resin compoundsare available from commercial chemical concerns which may be utilized inthe present invention. These plastic impregnated fibers or roving,generally referred to as glass filled epoxics, are usually supplied onspools ready for use by the manufacturer. The most common use heretoforefor this product has been for use in filament winding by the electricalindustry and for pressure vessels, rocket cases, tubular and tank typestructures. Any suitable type of glass reinforcing strands or roving maybe used in combination with any of various compounds of epoxy resins.For maximum strength, a ratio by weight of approximately 70% glassroving to 30% epoxy resin is recommended.

A typical composition for the glass roving may be, for example: siliconedioxide, 26 percent; aluminum oxide, 64 percent; magnesium oxide,percent. Such a composition provides a low alkali magnesia aluminasilicate glass of extremely high tensile strength. When combined withany selected epoxy resins, this glass filled epoxy has been tested toindicate a tensile strength on the order of 450,- 000 p.s.i. The abovedescribed glass filler is merely an example of one composition which maybe employed in carrying out the present invention as numerous otherrovings may also be used composed of high strength specialty glass, highmodules glass, or quartz fibers.

Mechanical damage is the sole factor having any significant effect onthe strength of a glass fiber reinforced plastic rail joint bar, whileon the other hand a steel rail joint bar is also affected by time,static load, cold flow, exposure to the elements, annealing, stresscorrosion and cracking, and crack propagation. In order to utilize to amaximum advantage the inherent strength of a glass fiber reinforcedepoxy resin in connection with the formation of a rail joint bar, anovel method has been devised whereby the epoxy resin impregnated rovingis arranged in a particular manner prior to curing to produce the finalrail joint bar.

The bolt holes in the joint bar are, as previously indicated,customarily located in the zone of the horizontal neutral axis of thebar and the force of the bolts against the web of the bar firmly clampsit to the head and base of the rail. Thus, the head and base of the railcorrespond generally to the top and bottom flanges of a beam and asusual the upper portion of the bar is in compression while the bottom ofthe bar is in tension.

For the sake of simplicity in carrying the invention into effect, it isproposed to provide a matrix or core M or M of the type generally shownin FIGS. 4-7 of the drawings.

The matrix M may be of any suitable cross-sectional shape, but thoseshown in FIGS. 4-6 may be considered typical.

According to FIG. 4, the matrix M includes a center member 10 ofsubstantially the length and height of the bar specifications. Themember 10 is flanked by side members 11 at opposite faces thereof andwhich may have the outwardly curved edge flange portions 12. Also thecentral horizontal portion of the matrix is provided with thimbles T tofacilitate the making of holes to receive the bolts in the finishedproduct.

According to FIG. 6, the matrix M may consist of separate longitudinallydivided and mating sections 13 and 14 which receive the thimbles Tbetween them. To ensure quick registry of the half-sections of thethimbles, the adjacent edge portions of the sections 13 and 14 may beprovided with suitable interlocking portions 15.

FIGS. 8 and 9 illustrate flat circular bolt hole reinforcing discs 16and cruciform reinforcing members 17. These elements 16 and 17 may beused alone or in conjunction with the primary matrix M. Preferably,these members are stamped out of commercially available sheet materialimpregnated with an epoxy resin now sold in dry form and then activatedchemically to become a part of the entire synthetic resin assembly.

FIGS. 12 and 13 show a bar whose web is relatively thick as comparedwith the web of other bars shown. A joint bar preferably does not fitthe profile of the fishing of the rail precisely so as to providetake-up for wear and to insure maximum clamping effect. In the case ofheadfree bars, the latter engage the head-web fillet of the rail at thetop while the bottom does not engage the base web fillet, but slidablyengages the inclined upper face of the rail base. Thus, when boltpressure is applied the base of the bar slides up the rail base and thehead firmly engages the rail fillet.

FIGS. 14 and 15 show how the non-metallic bars may be readily appliedwith a metal cladding such for example as shown in Lansing Patent No.2,702,161 dated February 15, 1955. This cladding may be applied byplacing the same in the mold at the time of manufacture or may beapplied before installation. In the patent, referred to, the metalpieces extend throughout the length of the bars and may be used with thebars of the present case, or alternatively, they may be medially spacedto provide a gap for the purposes described in Lansing Patent No.2,989,240 dated June 20, 1961.

In the process of manufacture, the matrix M is placed in a jig so thatthe epoxy resin roving or strand 20 may be wrapped around and about thematrix as illustrated in FIG. 10. These strands may be wound about thematrix longitudinally, as shown, or transversely, according to thespecifications of the bar. Moreover, the strands may be crossed in theform of a grid, and also diagonally at desired portions of the bar.

In order to secure maximum longitudinal rigidity in the bar the strandsmay be wound longitudinally of the bar with the intermediate strandspassing around the thimbles T in a continuous figure-8 pattern from oneend of the bar to the other. In other words, a strand thus wound wouldpass around say, the bottom of one thimble, and then cross over to passaround the top of the next adjacent thimble and so on to the oppositeend of the bar.

Thereafter, the epoxy winding and its matrix may be placed in a mold asshown for example in FIG. 11. This mold preferably includes upper andlower sections 22 and 23 whose complementary sections are formed withthe profile of the bar intended to fit in the rail fishing. Also themember 23 preferably has the bolt hole forming projections 24 whichextend from the lower half of the mold into the upper half. This upperhalf is provided with a cavity 25 which conforms to the outer profile ofthe bar which receives pressure of the bolts.

After the desired number of windings of the strand material have beenmade on the matrix according to the desired size of the joint bar, themold assembly is cured by heating. Many of the thermoplastic resins maybe cured by means of a single heat, While others may require a post-curein order to achieve maximum physical properties. An exemplary cure cyclewhich may be used in the formation of the present rail joint bar whenproduced with epoxy resin designated EP 787, as produced by U.S.Polymeric Chemicals, Inc., is as follows:

Cure cycle-l hour at 180200 F. Post Cure-1 hour at 250-300 F.

After the appropriate curing has been achieved and the joint bar removedfrom the mold, it is ready for immediate use, although some epoxy resinsmay increase in strength for about 21 days after curing and thereforeshould be stored for this period.

By way of further illustrating the range of the invention, reference maybe made to FIGS. 12, 13 and 14.

In FIGS. 13 and 14, the bar B is substantially in the form of a solidrectangle having the rail fishing engaging surfaces 27 and 28 with aflat outer face 29 lying substantially in a plane intersecting the headand foot of the bar, thus providing a web 30 of relatively greatthickness to receive the pressure of the bolts to be transmitted to thehead and foot.

In FIGS. 14 and 15, the bar B2 is of a cross section substantially likethat of FIG. 1 but having upper spaced cladding strips 31 and 32 for thehead, and lower spaced cladding strips or shims 33 and 34 at the foot ofthe bar.

Referring further to FIGS. 14 and 15, it is pointed out that the steelshims or cladding may be readily used with an electrically insulatingdimensionally stable thermosetting resin such as epoxy resin, becauseboth in a composite structure follow Hookes Law. The epoxy resins havesubstantially a coefficient of expansion value sufficiently close enoughto the coefficient of expansion value of the steel utilized, and,likewise, have a modulus of elasticity value comparable to that ofsteel, and said modulus of elasticity can be determined in the samemanner as the modulus of elasticity value of steel with respect to thecompleted insulated joint. Moreover, since the insulated joint includingthe component parts of the invention are used under all conditions ofheat and moisture, the components thereof must not only follow HookesLaw but they must also have substantially close enough and similarco-eflicients of expansion and contraction. Of course, the electricallyinsulating resin material is dimensionally stable when static anddynamic loads are imposed thereon.

I claim:

1. A nonmetallic rail joint bar including head and base portionsconnected by a web, said web comprising, an elongated core including anintermediate resin impregnated strip having other strips at oppositesides thereof and whose top and bottom edges turn outwardly, andlongitudinally disposed strands of glass fibers impregnated with athermosetting resin extending from end to end thereof and about saidedges, and also having openings in the web spaced to receive the shankof a bolt.

2. A non-metallic rail joint bar according to claim 1, including, discsof reinforcing material having openings registering with the bolt holeopenings in the intermediate portion of said core.

3. A non-metallic rail joint bar according to claim 1, wherein,cruciform reinforcing members are embedded in the web at the location ofthe bolt holes.

4. A non-metallic rail joint bar according to claim 1, including,annular insulating thimbles embedded in said webs and projectinglaterally from the core to receive the joint bolts.

5. A rail joint bar comprising, a body including head and base portionsconnected by a web, said body provided with a vertically extending resinimpregnated core whose top and bottom edges project into said head andbase portions respectively, a plurality of longitudinally disposedstrands of glass fibers impregnated with a thermo-setting resinextending from end to end of said body and about said edges tocompletely envelope said core, and said body also having a plurality ofspaced apart openings through the web thereof to receive the shank of abolt.

6. A rail joint bar according to claim 5, wherein, said core islongitudinally divided along a line passing through said openings andeach divided portion includes interlocking mating edges.

References Cited by the Examiner UNITED STATES PATENTS 2,670,136 2/1954Moses 238- 3,056,706 10/ 1962 Knoppel 52309 3,186,866 6/1965 Claeysl6l93 FOREIGN PATENTS 919,547 2/1963 Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

R. A. BERTSCH, Assistant Examiner.

1. A NON-METALLIC RAIL JOINT BAR INCLUDING HEAD AND BASE PORTIONSCONNECTED BY A WEB, SAID WEB COMPRISNG, AN ELONGATED CORE INCLUDING ANINTERMEDIATE RESIN IMPREGNATED STRIP HAVING OTHER STRIPS AT OPPOSITESIDES THEREOF AND WHOSE TOP AND BOTTOM EDGES TURN OUTWARDLY, ANDLONGITUDINALLY DISPOSED STRANDS OF GLASS FIBERS IMPREGNATED WITH ATHERMOSETTING RESIN EXTENDING FROM END TO END THEREOF AND ABOUT SAIDEDGES, AND ALSO HAVING OPENINGS IN THE WEB SPACED TO RECEIVE THE SHANKOF A BOLT.